Buses and the Mersey Tunnels

[Nwales Bus]

Buses and the Mersey Tunnels
Having been an occasional traveller on buses between the Wirral and Liverpool City Centre. I have been wondering regarding the tolls charged to the buses.

With the toll for buses crossing the river £3.40 or £2.80 with the tag, if the operators are paying full price this would lead to Stagecoach and Arriva paying hundreds of pounds every day

Therefore i was wondering do bus operators receive a discount

Thanks in advance